7. To determine whether caffeine consumption affects the ability to solve math problems, a researcher had one group solve math problems after taking a cup of caffeinated drink and another group solve...

7. To determine whether caffeine consumption affects the ability to solve math problems, a researcher had one group solve math problems after taking a cup of caffeinated drink and another group solve math problems after taking a cup of water. The group who took the caffeinated drink completed 35 problems in one hour and the group that had water completed 20 problems in one hour. Assuming the number of problems solved is normally distributed in each group, what statistical test would be used to test the research hypothesis? Explain your answer.